Suppressors for firearms, also known as silencers, generally operate to reduce the audible noise or sharp report of a firing weapon by means of reducing and controlling the energy level of attendant propellant gases. Generally, the techniques employed utilize a series of baffles which control and delay the flow, expansion, and exiting of propellant gases, forcing the propellant gases to pass through various temperature absorbent materials, or a combination of these or functionally similar techniques to reduce the temperature and abrupt discharge of propellant gases. The result achieved is a corresponding reduction in the noise produced by the exiting propellant gases.
Up to the present time, known silencers for hand firearms can be generally classified into two groups. In one group, the discharge and propellant gases that follow the bullet into the silencer are stored for a short period of time in a plurality of successive chambers which are closed to the outside. This produces a controlled expansion of the propellant gases through each chamber reducing their temperature and pressure. In a second group, at least a portion of the propellant gases are diverted to exterior coaxial chambers through a plurality of passages between inner and outer walls which is more complex, but can provide more opportunities to delay and cool the gases, and hence reduce the muzzle sound level.
The generic silencer baffle, used in the first group of silencers, is a flat disk with a cut-out for a bullet passage and resembles a washer from a hardware store. Other baffles are more complex cone or funnel shapes, or are shaped like a washer with a raised area around the bullet aperture to cause resistance to the passage of the propellant gases. The best of these are known as ‘K’ or ‘M’ baffles because their shape somewhat resembles those letters, and are used as the industry standard. Another type of baffle is an elliptical shaped flat baffle placed within the silencer body at an angle. This type of baffle is known as a ‘slant’ or asymmetric baffle. Waiser's use of slanted baffles (1981, U.S. Pat. No. 4,291,610) was perhaps the first instance of such a design and he positioned them in alignment about the longitudinal axis. Waiser, as well as a Russian design for the Makarov pistol, showed the baffles rotated with respect to the longitudinal axis with the head/toe in, or almost in, contact. Slanted asymmetric baffles have also been used by Taguchi (1986, U.S. Pat. No. 4,584,924). Taguchi's patent specifies flat-faced slanted-baffles at 90 degree rotations around the longitudinal axis with respect to the previous baffle.
Sometimes silencers of any baffle style are combined with heat absorbing mesh or metallic pellets which have the problem of needing replenishment as they become clogged or worn out. To keep propellant gases from escaping with the bullet, the more efficient designs employ ‘wipes’ which are generally elastomer disks with an ‘X’ cut in the center to allow the bullet to pass. The downside of wipes is that service life is very limited to well under 100 shots.
Gaddini (2003, U.S. Pat. No. 6,575,074) has created a design of the second group of silencers by combining symmetric baffles with round coaxial spacers and cut-outs. Each spacer formed just one chamber between itself and the outer tubular housing.
Some silencer designs have made use of square tubing to simplify construction. German patent (DE-AS Pat. No. 2,229,071) and Fishbaugh (1990, U.S. Pat. No. 4,974,489) uses square tubing that is not in contact with the outer tubular casing and does not form multiple chambers between the outer side of the square tubing and the inner side of the outer tubular casing. Fishbaugh uses square tubing sections as a frame for mounting baffles, which are rather symmetric in nature. Further, the square tubing in Fishbaugh is not in contact with the outer tube, and has a single divider forming just two coaxial chambers in the entire silencer.
Finally, White (2006 U.S. Pat. No. 7,073,426) discloses a combination of slanted baffles and round-tube spacers used in conjunction with a flat first baffle.
One or more disadvantages of previously known silencers may be eliminated by the silencer of the present invention.